The invention relates generally to wafer mounting structures for pickup tubes.
In certain types of pickup tubes, such as camera tubes, a thin wafer of a semiconductor, or other material, is mounted within an end portion of an evacuated tubular envelope. For example, in the silicon vidicon, an extremely thin target wafer of silicon is ordinarily mounted proximate and parallel to a transparent light receiving faceplate portion of an evacuated envelope.
Various structures have been employed in the prior art to mount such target wafers, with a varying degree of success. The prior art structures and methods have generally employed specially formed retaining rings, and/or spring mounting means, requiring costly and time consuming assembly and/or alignment operations.
In operational respects, such prior art structures have also proven deficient. For example, with such structures, vibration of the central portion of the wafer may occur whenever the tube is subjected to vibration or shock. In this manner, microphonics may be introduced during the operation of the tube. For this, and other reasons, tubes utilizing such mounting structures have often been restricted in the degree of shock or vibration to which they could be subjected and yet remain operational.